Burglar-alarm.



C. H. SMITH. BURGLAR ALARM.

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0. H. SMITH. BUBGLAR ALARM.

APPLICATION FILED 001. 6, 1909.

Patented Sept. 20, 1910.

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CALVIN H. SMITH, OF BESSEMER, ALABAMA.

BURGLAR-ALARM.

Specification of Letters Patent.

Patented Sept. 20, 1910.

Application filed October 5, 1909. Serial No. 521,039.

To all whom it may concern:

Be it known that I, CALVIN H. SMrrI-I,

' citizen of the United States, residing at Bessemer, in the county ofJefferson and State of Alabama, have invented certain new and usefulImprovements in Burglar- Alarms, of which the following is aspecification.

This invention relates to burglar alarms and refers to a mechanicaldevice which is adapted to be set into operation by walking upon aplatform which is positioned within the floor.

An object of this invention is to provide an improved alarm of thisnature which is especially applicable to store-houses and the like,where it is desired to set a sounding device into motion which islocated in an adjacent room or chamber to that in which the burglarenters.

The invention has for a further object the provision of a mechanism forsounding an alarm which is of simple construction, so that the same canbe readily positioned within the floor of a building and one which canbe easily set and which is positive in its operation when tripped.

For a full understanding of the invention and the merits thereof andalso to acquire a knowledge of the details of construction, reference isto be had to the following description and accompanying drawings, inwhich:

Figure 1 is a perspective view of a building partially in section,disclosing the improved alarm applied thereto; Fig. 2 is a sectionalview through the sounding device; and, Fig. 3 is a longitudinal verticalsection through the tripping mechanism.

Corresponding and like parts are referred to in the followingdescription and indicated in all the views of the drawings by the samereference characters.

Referring to the drawings, the numeral 10 designates the flooringbeneath which the improved trip mechanism is located. Disposed beneaththe flooring is a base 11 which is suitably supported beneath the sameand which is provided with guides 12 which are disposed in spacedrelation and in longitudinal alinement upon the base 11 and which areprovided with central slots 13 arranged vertically therein for theaccommodation of a rack 14. The rack .14 is formed of a longitudinalbar, preferably of metal, although any material may be used, whichcarries a plurality of teeth 15 in its upper edge into which is engagedthe lower extremity of a tripping lever 16 which is pivotally mountedthrough the upper end of the guide .12. The tripping lever 16 isretained in engagement with the teeth 15 by the provision of a spring 17which is secured at its opposite extremities against the under side ofthe floor 10 and to the upper arm of the tripping lever 16. A trippingpin 18 is carried by the upper arm of the lever 16 and extends throughan aperture 19 formed in the floor 10. For the purpose of depressing theupper end of the tripping lever or trip 16, a platform 20 is employedwhich is hingedly disposed upon the uoper face of the floor 10 and is sopositioned as to engage its under face against the upper extremity ofthe trip pin 18. The sprmg 17 is of such a strength as to normally holdthe pin 18 upwardly to hold the platform slightly above the upper faceof the floor 10 and is adapted to yield upon the weight of a person whosteps upon the platform.

The rear end of the rack 14L is connected to a cable 21 which extendsbeneath the floor 10 to a wall 22 or the like, where the cable 21 ispassed over a pulley 23 in order to change the direction of the cable.As is disclosed in Fig. 1, the cable is extended upwardly against thewall 22 through an upper floor 24: and is engaged over a second pulley.25 which supports the cable 21 in such a manner that it is extended tothe sounding device, indicated as 26.

For the purpose of drawing the rack 14: forward, the same is providedwith a cord 27 which extends outwardly from the rack 14: and is engagedover a roller 28 from which the cord 27 is extended upwardly and througha small aperture 29 formed in the floor 10. The upper extremity of thecord 27 carries a ring 30 or the like, to prevent the cord 27 frompassing downwardly through the floor 10, and also for the purpose offorming a hand hold, whereby the operator is capable of drawing the cord27 upwardly and to thereby set the rack 14-. The sounding device whichis indicated by the numeral 26 in Fig. 1, includes a casing 31, as isdisclosed in Fig. 2, within which is mounted a bell 32. A frame 33 ismounted in the casing 31 and against one of the sides thereof, whichsupports a spring actuated mechanism 34 for vibrating a clapper 35. Thespring mechanism 34 is provided with an escapement 36 which iscontrolled by an arm 37, the arm 37 being extended upwardly toward theupper end of the casing 31. The cable 21 is extended into one end of theeasing 31 and is connected to a link 38 which in turn carries the outerextremity of a spring 39. The spring 39 is secured to an eye bolt 40which is carried upon the oppo site end of the casing 31 and normallydraws the cable 21 inwardly of the casing 31. The link 38 is providedwith an abutment 41 which is engaged against the arm 37 in order to holdthe escapement 36 from operation and to thereby prevent the vibration ofthe clapper 35 against the bell 32 when the spring mechanism 34 iswound.

In the operation of the device when it is desired to set the same, theoperator grasps the ring 30 and draws the cord 27 upwardly through thefloor 10. This action causes the rack 14 to move forwardly toward theroller 28 and permits the tripping lever 16 to ride over the teeth 15until the abutment 41 is engaged closely against the arm 37 to preventthe vibration of the same. As the escapement mechanism is thus held frommove: ment, the spring mechanism 34 is wound and the alarm is thus set.

hen the platform 20 is stepped upon,

the Weight of the person throws the platform 20 downwardly and depressesthe trip pin 18, whereby the upper end of the lever 16 is depressed tocause the lower end of the lever 16 to be raised from the teeth 15 andto permit of the sliding of the rack 14: backwardly through the guides12. The spring 39 is connected to the cable 21, as

hereinbefore set forth, whereby a tension is exerted upon the cable 21to draw the same inwardly of the casing 31 upon the release of thetripping lever 16. WVhen the rack 14c is therefore released, the spring39 draws the cable 21 inwardly of the casing 31 and carries the link 38and abutment 41 back wardly therewith, whereby the arm 37 is releasedand the escapement 36 is permitted to operate. The spring mechanism 34now operates the clapper 35 to strike the bell or gong 32, thus soundingthe alarm.

Having thus described the invention what is claimed as new is:

An alarm including a base, spaced guides disposed on said base, a rackslidably disposed between said guides and having the teeth thereof inthe upper edge, a tripping lever carried by one of said guides, atripping pin carried by said lever and extended upwardly through thefloor, a platform disposed upon the floor over said tripping pin, a cordextended from the forward end of said rack and through said fioo-r, aring carried by said cord for engagement with the hand of the operatorto move said rack forwardly, a cable carried upon the rear end of saidrack, a spring connected to said cable to hold said rack normally in abackward. position and a sounding device connected to the rear end ofsaid cable.

In testimony whereof I aflix my signature in presence of two witnesses.

CALVIN H. SMITH. [11. s.]

WVitnesses:

J. A. Es'rns, W. P. GUNN.

